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Biomedical subjects

Michael Kramer

Publications and source records attributed to Michael Kramer.

At least 19 recordsLinked to original sources
PubMed2006

Influenza vaccination in German health care workers: effects and findings after two rounds of a nationwide awareness campaign.

In Germany, despite longstanding recommendations for influenza vaccination, uptake among health care workers (HCW) is poor. We conducted and evaluated a 2-year nationwide campaign to increase influenza vaccination rates among German HCW. The campaign was tailored to the results of a baseline survey and included the distribution of information material to all German hospitals (n approximately 2000) and engagement of stakeholders, such as professional HCW associations. Human and financial resources consisted of one full-time public health scientist (2 months) and approximately USD 45,000 to produce and distribute materials. We evaluated the intervention in a survey among a systematic sample of HCW in a sample of selected 20 hospitals. HCW were stratified by profession and asked to self-administer a questionnaire inquiring about self-perceived risk for influenza, belief of effectiveness of the vaccine, and influenza vaccination before the starting season (2003/2004) as well as the previous two seasons (2001/2002, 2002/2003). Three hundred and ninety-six of 800 (50%) HCW who were addressed in the evaluated hospitals participated in the evaluation survey. The overall influenza vaccination rate among respondents increased from 21% (2001/2002) to 26% (2003/2004), which was mostly due to a significant increase among physicians (2001/2002: 21%; 2003/2004: 31%; nurses: 20% and 22%, respectively). Significantly more physicians than nurses felt at increased risk for influenza and believed that the vaccine is very effective. Increased uptake among physicians (compared to nurses) was likely due to physicians' higher awareness of their risk and trust in the vaccine. In the future it may be necessary to address nurses differently than physicians. We conclude that a national campaign with very limited resources is feasible and capable of achieving measurable results in a short time frame.

Cross Infection↗
PubMed2006

Comparison of Gram and Kopeloff stains in the diagnosis of bacterial vaginosis in pregnancy.

Bacterial vaginosis (BV) is commonly diagnosed by using the Nugent score, a semiquantitative scoring system to evaluate bacterial morphotypes on Gram stain of vaginal secretions. Some authors have suggested using the Kopeloff modification of the Gram stain. Asymptomatic BV in pregnancy has been associated with adverse outcomes. We performed both stains on simultaneously collected vaginal smears from 2652 women at 24-26 weeks of gestation. Gram staining gave significantly higher (more abnormal) Nugent scores than Kopeloff staining. Compared to the Kopeloff stain, the number of specimens graded as indeterminate or consistent with BV by Gram stain increased by 29% (469 versus 364, P<.001). Interrater reliability of the Nugent score (n=413) for Kopeloff staining was significantly better than Gram staining (agreement=74% versus 63%, intraclass correlation coefficient=0.87 versus 0.79, P<.05, 95% confidence intervals 0.85-0.89 and 0.75-0.82, respectively).

Adult↗
PubMed2006

Preeclampsia, gestational hypertension and intrauterine growth restriction, related or independent conditions?

OBJECTIVE: Preeclampsia, gestational hypertension, and unexplained intrauterine growth restriction may have similar determinants and consequences. In this study, we compared determinants and perinatal outcomes associated with these obstetric conditions. STUDY DESIGN: We analyzed 39,615 pregnancies (data from the WHO Antenatal Care Trial), of which 2.2% were complicated by preeclampsia, 7.0% by gestational hypertension, and 8.1% by unexplained intrauterine growth restriction (ie, not associated with maternal smoking, maternal undernutrition, preeclampsia, gestational hypertension, or congenital malformations). We compared the risk factors associated with these groups. Fetal death, preterm delivery, and severe neonatal morbidity and mortality were the primary outcomes. Logistic regression analyses were adjusted for study site, socioeconomic status, and (if appropriate) birth weight and gestational age. RESULTS: Diabetes, renal or cardiac disease, previous preeclampsia, urinary tract infection, high maternal age, twin pregnancy, and obesity increased the risk of both hypertensive conditions. Previous large-for-age birth, reproductive tract surgery, antepartum hemorrhage and reproductive tract infection increased the risk for gestational hypertension only. Independent of maternal age, primiparity was a risk factor only for preeclampsia. Both preeclampsia and gestational hypertension were associated with increased risk for fetal death and severe neonatal morbidity and mortality. Mothers with preeclampsia compared with those with unexplained intrauterine growth restriction were more likely to have a history of diabetes, renal or cardiac disease, chronic hypertension, previous preeclampsia, body mass index more than 30 kg/cm2, urinary tract infection and extremes of maternal age. Conversely, unexplained intrauterine growth restriction was associated with higher risk of low birth weight in previous pregnancies, but not with previous preeclampsia. Both conditions increased the risk for perinatal outcomes independently but preeclampsia was associated with considerable higher risk. CONCLUSION: Preeclampsia and gestational hypertension shared many risk factors, although there are differences that need further evaluation. Both conditions significantly increased morbidity and mortality. Conversely, preeclampsia and unexplained intrauterine growth restriction, often assumed to be related to placental insufficiency, seem to be independent biologic entities.

Female↗
PubMed2006

Comparison of the relative benefits of 2 versus 10 days of soft collar cervical immobilization after acute whiplash injury.

OBJECTIVE: To investigate the effects of 2-day and 10-day immobilization of the cervical spine on pain, range of motion (ROM), and disability of patients with Quebec Task Force (QTF) grade II whiplash injuries. DESIGN: Randomized controlled trial. SETTING: University hospital emergency department. PARTICIPANTS: Seventy patients with acute QTF grade II whiplash injuries. INTERVENTIONS: At the intake examination within 24 hours after the whiplash trauma, the patients were randomized to 2 therapy groups (2-d or 10-d immobilization with a soft cervical collar). All patients received pain drugs (nonsteroidal anti-inflammatory drugs) and after 7 days, all patients started a standardized physiotherapy program 2 to 3 times a week. MAIN OUTCOME MEASURES: Patients' pain and disability scores were assessed using visual analog scales and ROM was assessed using a goniometer. All parameters were measured within 24 hours after injury and after 2 and 6 months. RESULTS: After 2 months, the different periods of immobilization (2d or 10d) were associated with comparable improvements in pain symptoms (median, 4.60 vs 4.65), ROM (median, 100.0 degrees vs 117.5 degrees ), and disability score (median, 4.90 vs 5.15). No statistically significant differences could be identified between the 2 treatment groups. After 6 months, persistent pain was reported by 4 patients in each group (12.5%). CONCLUSIONS: In patients with QTF grade II whiplash injuries, there is no short- or long-term difference between 2-day and 10-day immobilization with a cervical collar in terms of pain, ROM, or disability.

Acute Disease↗
PubMed2006

Injuries of the cervical spine in patients with ankylosing spondylitis: experience at two trauma centers.

OBJECT: The cervical spine in a patient with ankylosing spondylitis (AS) (Bechterew disease) is exposed to maximal risk due to physical load. Even minor trauma can cause fractures because of the spine's poor elasticity (so-called bamboo spine). The authors conducted a study to determine the characteristics of cervical fractures in patients with AS to describe the standard procedures in the treatment of this condition at two trauma centers and to discuss complications of and outcomes after treatment. METHODS: Between 1990 and 2006, 37 patients were surgically treated at two institutions. All patients were examined preoperatively and when being discharged from the hospital for rehabilitation. Single-session (11 cases) and two-session anterior-posterior (13 cases), anterior (11 cases), posterior (two cases), and laminectomy (one case) procedures were performed. The injury pattern, segments involved, the pre- and postoperative neurological status, and complications were analyzed. Preoperative neurological deficits were present in 36 patients. All patients experienced improvement postoperatively, and there was no case of surgery-related neurological deterioration. In patients in whom treatment was delayed because of late diagnosis, preoperative neurological deficits were more severe and improvement worse than those treated earlier. The causes of three deaths were respiratory distress syndrome due to a rigid thorax and cerebral ischemia due to rupture of the vertebral arteries. There were 12 perioperative complications (32%), three infections, one deep venous thrombosis, five early implant failures, and the three aforementioned fatalities. There were no cases of epidural hematoma. In all five cases in which early implant failure required revision surgery, the initial stabilization procedure had been anterior only. A comparison of complications and the outcomes at the two centers revealed no significant differences. CONCLUSIONS: The standard intervention for these injuries is open reduction, anterior decompression and fusion, and anterior-posterior stabilization; these procedures may be conducted in one or two stages. Based on the early implant failures that occurred exclusively after single-session anterior stabilizations (five of 10--a failure rate of 50%), the authors have performed only posterior and anterior procedures since 1997 at both centers. Diagnostic investigations include computed tomography scanning or magnetic resonance imaging of the whole spine, because additional injuries are common. The causative trauma may be very slight, and diagnosis may be delayed because plain radiographs can be initially misinterpreted. In cases in which diagnosis is delayed, patients present with more severe neurological deficits, and postoperative improvement is less pronounced than that in patients in whom a prompt diagnosis is established. Because of postoperative pulmonary and ischemic complications, the mortality rate is high. In the present series the mortality rate was lower than the mean rate reported in the literature.

Adult↗
PubMed2005

Surface electromyography of the paravertebral muscles in patients with chronic low back pain.

OBJECTIVE: To investigate the differences in the electromyographic signals of patients with chronic low back pain (CLBP) and healthy subjects. DESIGN: Cross-sectional study with a matched-pair design. SETTING: University hospital. PARTICIPANTS: Thirty-one patients with CLBP and 31 healthy, matched-pair controls. INTERVENTIONS: The mean rectified surface electromyographic amplitude and muscle strength were measured during maximal voluntary contraction (MVC). During an endurance test at 60% of MVC, the electromyographic parameters of the 2 groups were compared.Main outcome measure Electromyographic measuring of local fatigue, which can be described with changes in the median frequency or by a different parameter of the power spectrum called frequency banding. RESULTS: The strength measurement revealed a deficiency of 40% in the patients and a deficit in the electromyographic amplitude of approximately 60%, compared with the control group. By pairwise comparison, the decrease in the median frequency during the endurance test was greater in the control group. In the frequency banding of the power spectrum, local fatigue was less pronounced in the CLBP patients in pairwise comparison. CONCLUSIONS: The back muscles of CLBP patients appear to be less fatigable than those of controls. The results can be explained by morphologic changes, but influences such as pain, avoidance of pain, and deconditioning, need to be considered when the results are assessed.

Action Potentials↗
PubMed2005

Device-assisted muscle strengthening in the rehabilitation of patients after surgically stabilized vertebral fractures.

OBJECTIVES: To investigate the effects of a device-assisted muscle strengthening exercise program on the surgically traumatized multifidus musculature and on the intact longissimus and iliocostal muscles and to assess the possible relationship between patients' reported pain symptoms and changes in muscle strength or changes in cross-sectional area (CSA) of the musculature. DESIGN: Open, prospective noncontrolled prepost intervention study. SETTING: University-affiliated center for ambulant physiotherapy. PARTICIPANTS: Fifteen patients who had undergone dorsal osteosynthesis for treatment of thoracolumbar vertebral fracture and who complained of persistent back pain. INTERVENTION: Twelve-week device-assisted training exercise program. MAIN OUTCOME MEASURES: Patients' pain score, muscle strength, and the CSA of the paravertebral musculature determined by magnetic resonance imaging (MRI) were assessed before and after the exercise program. RESULTS: MRI findings revealed no increase in the CSA of the multifidus muscle in any patient (median change, -.27 cm 2 ). All patients, however, exhibited hypertrophy of both the longissimus and iliocostal muscles (median change, 1.39 cm 2 ). Significant increase in muscle strength was observed in 14 of 16 patients (median increase, 56%; range, 0.7%-126.4%). The median overall pain score improved from 19 (range, 7-24) to 16 (range, 5-27). The change in muscle strength and muscle CSA, however, showed no correlation. There was also no correlation between increase in muscle strength and changes in pain scores. CONCLUSIONS: The device-assisted training program resulted in hypertrophy of the iliocostal and longissimus muscles and an increase in muscle strength in patients with surgically stabilized vertebral fractures. About half of the patients reported relief of pain. No correlation was found between hypertrophy, increase in muscle strength, and relief of pain. The surgically damaged multifidus musculature, however, did not show any change in CSA and was not accessible to rehabilitative measures.

Adult↗
PubMed2005

Tumor necrosis factor alpha leads to increased cell surface expression of CXCR4 in SK-N-MC cells.

Both host and viral factors play an important role in the pathogenesis of human immunodeficiency virus (HIV)-associated bran injury. In this study, the authors examined the interactions between tumor necrosis factor (TNF)-alpha, CXCR4, the alpha chemokine receptor, and three HIV isolates, including the T-tropic viruses, HIV-1(MN) and HIV-1(IIIB), and the dual tropic virus, HIV-1(89.6). The authors show by flow cytometry that treatment of differentiated SK-N-MC cells with TNF-alpha induces a significant increase in the cell surface expression of CXCR4 in a time- and dose-dependent manner. The effect is partly regulated at the level of transcription. To assess the biological significance of this finding, we show that TNF-alpha potentiates the ability of the above mentioned HIV isolates to induce neuronal apoptosis and that the effect is significantly reduced by pretreating cells with monoclonal antibodies to either CXCR4 and TNF-alpha. Together these results suggest that TNF-alpha may render neuronal cells vulnerable to the apoptotic effects of HIV by increasing the cell surface expression of CXCR4 and thus identify another mechanism by which TNF-alpha contributes to the pathogenesis of HIV-associated brain injury.

Apoptosis↗
PubMed2004

Solvent-preserved, bovine cancellous bone blocks used for reconstruction of thoracolumbar fractures in minimally invasive spinal surgery-first clinical results.

We investigated the osseointegration of solvent-preserved, xenogenous cancellous bone blocks in the treatment of unstable fractures of the thoracolumbar junction. In 22 patients, the anterior repair procedure was performed by thoracoscopy or minimally invasive retroperitoneal surgery. Twenty-two patients had undergone monosegmental anterior fusion and were surveyed prospectively. Solvent-preserved, bovine cancellous bone blocks were used in 11 patients; iliac crest bone graft was used in the others. Follow-up after 12 months included CT scans, which revealed successful osseointegration in eight out of 11 patients who had received autogenous iliac crest bone grafts, while three patients showed a partial integration. There were no graft fragmentations. In patients who had received solvent-preserved, xenogenous cancellous bone blocks, complete osseointegration was achieved at the graft-bone interface in only two out of 11 cases, after 1 year. Partial integration was found in three patients. In view of these results, autogenous iliac crest bone grafts are still the unrivalled standard for defect repair in spinal surgery.

Adolescent↗
PubMed2004

Operative vaginal delivery and neonatal and infant adverse outcomes: population based retrospective analysis.

OBJECTIVE: To compare the risk of neonatal and infant adverse outcomes between vacuum and forceps assisted deliveries. DESIGN: Population based study. SETTING: US linked natality and mortality birth cohort file and the New Jersey linked natality, mortality, and hospital discharge summary birth cohort file. PARTICIPANTS: Singleton live births in the United States (n = 11 639 388) and New Jersey (n = 375 351). MAIN OUTCOME MEASURES: Neonatal morbidity and mortality. RESULTS: Neonatal mortality was comparable between vacuum and forceps deliveries in US births (odds ratio 0.94, 95% confidence interval 0.79 to 1.12). Vacuum delivery was associated with a lower risk of birth injuries (0.69, 0.66 to 0.72), neonatal seizures (0.78, 0.68 to 0.90), and need for assisted ventilation (< 30 minutes 0.94, 0.92 to 0.97; > or = 30 minutes 0.92, 0.88 to 0.98). Among births in New Jersey, vacuum extraction was more likely than forceps to be complicated by postpartum haemorrhage (1.22, 1.07 to 1.39) and shoulder dystocia (2.00, 1.62 to 2.48). The risks of intracranial haemorrhage, difficulty with feeding, and retinal haemorrhage were comparable between both modes of delivery. The sequential use of vacuum and forceps was associated with an increased risk of need for mechanical ventilation in the infant and third and fourth degree perineal tears. CONCLUSION: Although vacuum extraction does have risks, it remains a safe alternative to forceps delivery.

Cohort Studies↗
PubMed2004

Simultaneous measurement of intramuscular pressure and surface electromyography of the multifidus muscle.

The anatomic proof of a spinal compartment and the clinical symptoms of compartment syndrome in patients with chronic back pain are inconsistent with the rarely met measuring criteria of intramuscular pressure (IMP). Previous studies assume a dependence of the IMP on spinal alignment (degree of lumbar spine flexion) and the degree of muscle activation. The significance of these disturbance variables in the interpretation of IMP could explain the above discrepancy. This study therefore investigates the influence of both a 30% increase in trunk flexion and alterations in muscle contraction from 100% to 60%. Sixteen healthy subjects participated in the study. The IMP and mean rectified amplitude of the multifidus surface EMG signal were determined at rest and 0 degrees and approximately 30 degrees of lumbar spine flexion, and they were compared. Subsequently, both parameters were measured during both 100% and 60% maximal voluntary contraction (MVC) of the muscle and then correlated. During rest and 0 degrees flexion, the median IMP was 9.3 mmHg (range 0.0-22.5) while the median mean rectified amplitude (MRA) of the EMG signal was 1.98 microV (range 1.32-7.38). In 30 degrees flexion, the median IMP went up to 24.3 mmHg (range 1.4-97.3) with hardly any increase in the median MRA of 2.32 microV (range 1.20-9.72). Under 60% MVC, the median IMP rose to 186.6 mmHg (range 15.4-375.4) and the median MRA to 21.02 microV (range 4.63-43.63). During 100% MVC, the median MRA increased to 34.38 microV (range 12.99-102.54) while the median IMP rose to 273.4 mmHg (range 90.4-395.1). Spearman's rank correlation coefficient for the IMP and MRA quotients of the 100/60% MVC values was r= -0.21. To sum up, it can be said that IMP was subject to great interindividual variation in all the experiments. This parameter is highly dependent on spinal alignment and muscular activity. Further studies are needed so that the IMP can be interpreted properly when diagnosing a chronic compartment of the erector spinae muscles.

Adult↗
PubMed2004

Hopelessness and terminal illness: the construct of hopelessness in patients with advanced AIDS.

OBJECTIVE: Understanding the construct of hopelessness in the context of a life-threatening or terminal illness is a complex and challenging undertaking. The objective of this study was to examine the construct of hopelessness in patients with advanced AIDS by examining the structure of the Beck Hopelessness Scale in this specific population. METHODS: For the past three decades, the primary measure used to study hopelessness in a variety of populations has been the Beck Hopelessness Scale. Several factor analytic studies have been published using this scale, with studies of nonclinical samples typically describing a two-factor model (optimism and pessimism), whereas clinical samples have consistently generated a third factor (lack of motivation to make changes). We used confirmatory factor analysis to analyze two data sets in patients with AIDS. RESULTS: Confirmatory factor analysis of the Beck Hopelessness Scale in two samples of patients with far advanced AIDS revealed a clear superiority for a three-factor model. SIGNIFICANCE OF RESULTS: The Beck Hopelessness Scale has unique characteristics when applied to a terminally ill population. The implications of these results for studies of terminal illness are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Heterogeneity of perinatal outcomes in the preterm delivery syndrome.

OBJECTIVE: Our aim was to document the differential neonatal morbidity and intrapartum and neonatal mortality of subgroups of preterm delivery. METHODS: This analysis included 38,319 singleton pregnancies, of which 3,304 (8.6%) were preterm deliveries (less than 37 completed weeks) enrolled in the World Health Organization randomized trial of a new antenatal care model. We classified them as preterm deliveries after spontaneous initiation of labor, either with or without maternal obstetric and medical complications; preterm deliveries after prelabor spontaneous rupture of amniotic membranes (PROM), either with or without obstetric and medical complications; and medically indicated preterm deliveries with maternal obstetric and medical complications. Severe neonatal morbidity and neonatal mortality were the primary outcomes. RESULTS: Fifty-six percent of all preterm deliveries were spontaneous, without maternal complications. Small for gestational age was increased only among the medically indicated preterm delivery group (22.3%). Very early preterm delivery (less than 32 weeks of gestation) was highest among PROM with complications (37%). For intrapartum fetal death and neonatal death, after adjusting by gestational age and other confounding variables, we found that the obstetric and medical complications preceding preterm delivery predicted the different risk levels. Conversely, for severe neonatal morbidity the clinical presentation, ie, PROM or medically indicated, predicted the increased risk. CONCLUSION: There are differential neonatal outcomes among preterm deliveries according to clinical presentation, pregnancy complications, gestational age at delivery, and its association with small for gestational age. This syndromic nature of the condition should be considered if preterm delivery is to be fully understood and thus reduced.

Adolescent↗
PubMed2003

Progress toward measles elimination in Germany.

While the former East Germany (FEG) achieved a reduction of measles incidence to <1 case per 100,000 population before reunification in 1990, the former West Germany (FWG) experienced significant measles morbidity. In 2001, according to statutory surveillance data, the incidence of measles was still higher in FWG than in FEG (8.7 vs. 0.7 cases/100,000 population). This article describes the development of the vaccination strategies in FEG and FWG, vaccination coverage, results of seroprevalence studies, measles surveillance in Germany, the epidemiology of a recent outbreak, and the role of laboratory diagnosis for measles control in Germany. Recent establishment of comprehensive nationwide surveillance and prevention programs to attain higher vaccine coverage have led to a decrease in measles incidence. However, further improvement of age-appropriate vaccine coverage and closure of immunity gaps in school-age children are necessary to eliminate measles in Germany.

Adolescent↗
PubMed2002

Massively parallel signature sequencing (MPSS) as a tool for in-depth quantitative gene expression profiling in all organisms.

Massively parallel signature sequencing (MPSS) is one of the newest tools available for conducting in-depth expression profiling. MPSS is an open-ended platform that analyses the level of expression of virtually all genes in a sample by counting the number of individual mRNA molecules produced from each gene. There is no requirement that genes be identified and characterised prior to conducting an experiment. MPSS has a routine sensitivity at a level of a few molecules of mRNA per cell, and the datasets are in a digital format that simplifies the management and analysis of the data. Therefore, of the various microarray and non-microarray technologies currently available, MPSS provides many advantages for generating the type of complete datasets that will help to facilitate hypothesis-driven experiments in the era of digital biology.

Cloning, Molecular↗